Spindle cell carcinoma (SpCC) of the lung is extremely rare, with an incidence of less than 0.5% among all lung malignancies. Neuroendocrine tumors are frequently associated with secondary primary malignancies. Here, we report a case of metachronous SpCC that occurred after treatment of a primary carcinoid tumor of the lung. The SpCC mass was successfully removed by lobectomy. In immunohistochemical analyses, the tissues were positive for cytokeratin 7 and vimentin.
Carcinoid Tumor* ; Incidence ; Keratin-7 ; Lung* ; Neuroendocrine Tumors ; Vimentin

The lungs are one of the most common visceral sites for metastatic disease. The identification of a metastasis from a second primary lung tumor is clinically important for patients with pulmonary metastases of an extrathoracic origin. Although the cytologic features of metastatic tumors involving the lung have been extensively described, making the cytologic diagnosis is usually not easy in the absence of clinical information. However, the immunohistochemical staining for many tumor markers and the different expressions of cytokeratin 7 and 20 are very useful in the diagnosis. This review presents the cytomorphological spectrum of metastatic tumors along with the immunohistochemical findings.
Humans ; Immunohistochemistry ; Keratin-7 ; Lung ; Neoplasm Metastasis ; Biomarkers, Tumor

The distinction of carcinomas involving periampullary region is often difficult, even in the surgically resected specimens. To examine the differences in the expressions of cytokeratin (CK) 7 and 20 in the periampullary carcinomas, we performed immunohistochemical studies on surgically resected 20 pancreatic duct adenocarcinomas (PDA), 13 distal bile duct adenocarcinomas (DBA), 10 duodenal adenocarcinomas (DA), and 18 ampulla of Vater adenocarcinomas (AVA). We analyzed the relationships between CK 7/CK 20 immunoprofile, and tumor cell differentiation and tumor size. We interpreted diffuse cytoplasmic reactivity found in > or =5% of tumor cells as positive. In the majority of cases, PDA were CK 7 /20 (95%), DBA CK 7 /20 (92.3%), DA either CK 7 /20 (40%) or CK 7 /20 (30%), AVA either CK 7 /20 (50%) or CK 7 /20 (44.4%). In DA, there was an increased CK 20 negativity in less differentiated (moderately or poorly differentiated) cases (p<0.05) and in larger (> or =5 cm) tumor size (p=0.049). In AVA, there was a tendency of increased CK 20 positivity in less differentiated cases (p=0.10). In conclusion, the CK 7/CK 20 immunophenotype is useful in the differentiation of periampullary carcinomas: the CK 7 /CK 20 immunophenotype strongly suggests DA or AVA, whereas the CK 7 /CK 20 immunophenotype suggests PDA or DBA.
Adenocarcinoma ; Ampulla of Vater ; Bile Ducts ; Cell Differentiation ; Cytoplasm ; Keratin-20 ; Keratin-7* ; Keratins* ; Pancreatic Ducts

Roughly 1% of mature cystic teratomas undergo malignant transformation. In particular, cutaneous-type adnexal neoplasms may occur in mature cystic teratomas. Sebaceous carcinomas, which arise from mature cystic teratomas, have rarely been observed, with only seven cases previously reported. Here, we present a case of a 69-year-old female who had pelvic pain for two weeks and who subsequently underwent bilateral salpingo-oophorectomy and hysterectomy. Her left ovary showed a unilocular cyst, measuring 22.0 cm in diameter, filled with sebaceous material and a few hairs. A luminally-protruding solid mass measuring 4.0 cm in diameter was also noted. Microscopic findings revealed lobular or diffusely arranged basophilic, atypical sebaceous cells connected to a typical mature cystic teratoma. Tumor cells demonstrated positive immunoreactivity for high molecular weight cytokeratin, cytokeratin 7, cytokeratin 19, epithelial membrane antigen, and carcinoembryonic antigen. Here, we present a case of sebaceous carcinoma arising from a mature cystic teratoma along with a review of previously published reports.
Basophils ; Carcinoembryonic Antigen ; Female ; Hair ; Humans ; Hysterectomy ; Keratin-19 ; Keratin-7 ; Keratins ; Molecular Weight ; Mucin-1 ; Ovary ; Pelvic Pain ; Teratoma

BACKGROUND: Micropapillary urothelial carcinoma of urinary bladder is a rare and aggressive subtype of urothelial carcinoma (UC). METHODS AND RESULTS: Seven UCs with a micropapillary component (MPC) were identified by reviewing 135 cystectomy specimens of UC (5.2% in incidence). MPC was associated with conventional UC in 6 cases and the plasmacytoid variant of UC in 1 case. Lymph node metastasis, that characteristically contained MPC was present in 60% (3 out of 5 cases of regional lymph node dissection). Three patients with extensive MPC showed laminar propria invasion (pT1; 33%) and perivesical fat invasion (pT3; 67%). Two out of 3 patients with extensive MPC showed distant metastasis into the colon after cystectomy. The colonic lesions showed exclusively micropapillary differentiation. Four patients with focal or moderate MPC (pT2, 25%; pT3, 75%) were alive without disease at the time of writing this article. All 3 cases with extensive MPC had surface and/or invasive MPC on the prior TURB specimen. Immunohistochemically, the tumor cells were positive for cytokeratin 7, cytokeratin 20, EMA and E-cadherin and tissue retraction spaces that simulate lymphatic spaces were negative for CD34 in all 7 cases. CONCLUSIONS: This study suggests that the micropapillary growth pattern in UC is a manifestation of aggressive behavior and UC with MPC must be included as part of the differential diagnosis when dealing with a metastatic lesion with a micropaillary structure.
Cadherins ; Colon ; Cystectomy ; Diagnosis, Differential ; Humans ; Keratin-20 ; Keratin-7 ; Lymph Nodes ; Neoplasm Metastasis ; Urinary Bladder ; Writing

Low-grade adenocarcinomas that primarily arise within the sinonasal tract are uncommon tumors. We report here on three cases of primary sinonasal low-grade adenocarcinomas. The patients were 2 females and 1 male with ages of 48, 57 and 64, respectively. Microscopically, the tumors had a well developed tubulopapillary growth pattern that consisted of columnar or pseudostratified cells with eosinophilic cytoplasm, round to oval nuclei and rare mitotic activity. On immunohistochemistry, the tumor cells were strongly positive for cytokeratin 7, but they were negative for cytokeratin 20, CDX-2 and p53. The Ki-67 labeling index was very low (mean: 1.9%). Two patients developed recurrent tumors at the primary site after the initial surgery, but all the patients are presently alive without metastasis 6 years 8 months, 8 years 8 months, and 11 months after the initial diagnosis. When considering the progress of these tumors, we think that it's important to understand the pathology of this entity to avoid underdiagnosis because a complete excision is required for effective treatment.
Adenocarcinoma* ; Cytoplasm ; Diagnosis ; Eosinophils ; Female ; Humans ; Immunohistochemistry ; Keratin-20 ; Keratin-7 ; Ki-67 Antigen ; Male ; Neoplasm Metastasis ; Pathology

The distinction between cholangiocarcinoma (CC) and metastatic colonic adenocarcinoma of the liver (MCA) is often difficult, particularly in needle biopsy and fine-needle aspiration specimens, if histologic features alone are used. To examine the differences in the expressions of the cytokeratin (CK) 7 and 20 in the CCs and MCAs, we performed immunohistochemical studies on surgically resected 19 CCs and 23 MCAs. We used monoclonal antibodies against CK 7 and CK 20, and applied microwave antigen retrieval technique on formalin-fixed, paraffin-embedded tissue. We interpreted diffuse cytoplasmic reactivity found in > or =5% of tumor cells as positive. CCs showed CK 7+/CK 20- immunophenotype in 63%, CK 7+/CK 20+ in 32%, CK 7-/CK 20+ in 5%, and CK 7-/CK 20- in 0%. MCAs exhibited CK 7-/CK 20+ immunophenotype in 87%, CK 7+/CK 20+ in 9%, CK 7-/CK 20- in 4%, and CK 7+/CK 20- in 0%. CK 20-reactive cells in CCs were frequently columnar in shape (p<0.05). In conclusion, the CK 7/CK 20 immunophenotype was useful in the differentiation of CCs from MCAs: the CK 7+/CK 20- immunophenotype strongly suggested CCs, whereas the CK 7-/CK 20+ immunophenotype strongly suggested MCAs.
Adenocarcinoma* ; Antibodies, Monoclonal ; Biopsy, Fine-Needle ; Biopsy, Needle ; Cholangiocarcinoma* ; Colon* ; Cytoplasm ; Keratin-20 ; Keratin-7 ; Keratins* ; Liver* ; Microwaves

BACKGROUND: Due to advancements in treatment of metastatic and advanced renal cell carcinoma (RCC), it has become increasingly important to diagnose metastatic RCC and the specific subtype. In this study, we investigated the diverse histologic features of metastatic clear cell renal cell carcinoma (CCRCC) cases in comparison with corresponding primary lesions. METHODS: We identified 119 metastatic CCRCC cases from 81 corresponding primary lesions diagnosed between 1995 and 2010 and evaluated the diverse histologic and immunohistochemical features of these lesions. RESULTS: A total of 44 primary lesions (54.3%) had a non-clear cell component in addition to a typical clear cell component. Of the 119 metastatic lesions, 63 lesions (52.9%) contained a non-clear cell component, and 29 metastatic lesions were composed of a non-clear cell component only. Rhabdoid features were the most frequent non-clear cell histology among the metastatic lesions. Metastatic CCRCCs mainly showed positive CD10 and epithelial membrane antigen staining and negative cytokeratin 7 staining. CONCLUSIONS: Metastatic CCRCC commonly showed a variety of histologic features. If there is a difficulty to diagnose metastatic CCRCC due to a variety of histologic features or small biopsy specimen, histologic review of the primary lesion and immunohistochemical analysis can help determine the correct diagnosis.
Biopsy ; Carcinoma, Renal Cell* ; Cellular Structures ; Immunohistochemistry ; Keratin-7 ; Mucin-1 ; Neoplasm Metastasis

BACKGROUND: Clear cell papillary renal cell carcinoma (CCPRCC) is a recently established subtype of renal epithelial tumor. The aim of this study was to identify the diagnostic criteria of CCPRCC with an emphasis on immunohistochemical studies, and to report three cases with concurrent other-type renal cell carcinoma (RCC). METHODS: A total of 515 RCC patients that consecutively underwent surgical resection at Seoul National University Hospital from 1 January 2010 to 31 December 2011 were screened. Each case was reviewed based on the histologic features and was evaluated immunohistochemically. RESULTS: A total of 15 CCPRCCs were identified, which composed 2.9% of the total RCCs. The mean age was 52 years, and the average tumor size was 1.65 cm. All 15 cases showed low nuclear grade, no lymph node metastasis and no distant metastasis. The CCPRCCs showed variable architectural patterns including cystic, trabecular, papillary, and acinar. All of the cases showed moderate to intense immunoreactivity for cytokeratin 7 (CK7). CD10 was negative or showed focal weak positivity. Three cases had concurrent other-type RCC, including a clear cell RCC and an acquired cystic disease-associated RCC. CONCLUSIONS: The strong CK7 and negative or focal weak CD10 expression will be useful for the diagnosis of CCPRCC.
Carcinoma, Renal Cell ; Humans ; Keratin-7 ; Lymph Nodes ; Neoplasm Metastasis ; Neprilysin

Acinar cell cystadenoma (ACA) is a very rare cystic lesion of the pancreas. The lining epithelium of ACA is morphologically identical to acinar cells of the pancreas. It is uncertain whether ACA is a benign neoplasm or cystic transformation of acinar glands but it is worthy to consider ACA in the differential diagnosis of other cystic neoplasms of the pancreas. We report here a 25-year old-woman who was operated on for a cystic mass of the pancreas. Grossly, a multilocular cystic mass containing clear serous fluid was observed. There was no communication between the cysts and the pancreatic ducts. Microscopically, cysts of various size were lined by columnar, cuboidal or flattened epithelial cells with a few foci of pseudostratification. The cells had granular apical cytoplasm and basally located nuclei with minimal atypia, the same as normal acinar cells. Metaplastic ossification was noted in the stroma. Immunohistochemically, the lining epithelium was positive for cytokeratin 7, antitrypsin and antichymotrypsin.
Acinar Cells* ; Cystadenoma* ; Cytoplasm ; Diagnosis, Differential ; Epithelial Cells ; Epithelium ; Keratin-7 ; Pancreas* ; Pancreatic Ducts ; Pancreatic Neoplasms